The present invention relates to a chlorella nurturing device, particularly, a chlorella nurturing device which can preferably be used at a place near the equator.
The present applicant has previously proposed various kinds of chlorella nurturing devices effectively utilizing solar rays. However, those proposals were performed only in consideration of their application to buildings or the like. The conventional chlorella nurturing device employed artificial light in an effective combination with solar rays. Such use was limited to highly advanced countries where artificial light sources could easily be obtained. Therefore, in order to nurture chlorella in a most primitive way, it was necessary to make an artificial pond and only to utilize solar rays. However, in the case of nurturing chlorella in an artificial pond, all of the solar rays are normally reflected on the upper surface of the water at an incidence angle of about 45.degree. or less, so that no rays enter the pond. For this reason, the efficiency of producing chlorella in this way is very low.
However, one would think that if such a method of nurturing chlorella in an artificial pond was applied to a place nearer to the equator which received an abundance of direct solar rays, its efficiency might be greatly increased. However, there exist many birds and insects in those equatorial areas and consequently an artificial pond would be polluted by those living things. Furthermore, the pond sometimes overflows its banks because of storms, or the nurtured chlorella becomes diluted unexpectedly. Until now, such problems could not be dealt with.